葡萄糖和木糖共发酵生产L-乳酸的培养基和培养条件响应面优化

为提高米根霉利用葡萄糖、木糖共发酵产L-乳酸的产量，在单因素试验基础上，采用响应面法进行培养基和培养条件优化的试验方案设计。利用Design Expert软件对其结果进行二次回归分析，获得的最佳产酸条件为：葡萄糖100g/L、木糖50g/L、 (NH4)2SO4 3.0g/L、KH2PO4 0.3g/L、摇床转速180r/min、温度32℃、接种量12%、装液量50mL。该条件下摇瓶发酵72h，L-乳酸产量为119.216g/L，转化率为79.48%。

Optimization of Co-fermentation of Glucose and Xylose for L-Lactic Acid Production Using Response Surface Methodology

The medium composition and culture conditions for L-lactic acid production via the co-fermentation of glucose and xylose with Rhizopus oryzae were optimized by response surface methodology. A 7-factor, 3-level central composite design was performed based on single factor experiments and the quadratic regression analysis of the experimental results was conducted by using Design Expert software. The optimum medium composition (g/L) was glucose 100, xylose 50, (NH4)2SO4 3.0 and KH2PO4 0.3, and the optimum culture conditions were medium volume in a 250 mL flask of 50 mL, shaking table speed of 180 r/min, inoculation amount of 12% and culture temperature of 32 ℃. Under these conditions, the concentration of L-lactic acid reached up to 119.216 g/L after 72 h fermentation and the conversion rate was up to 79.48%.